On the other hand, M&S said basic pay could increase by 15 per cent from next April to £8.50 per hour, handing hourly pay rises to around 62,000 shopfloor employees.

"We have been contacted by many of our members in Marks and Spencer who are very concerned about the proposed big changes in their pay and pension, along with the threat of Autumn store closures," said David Gill, the national officer for shopworkers' trade union Usdaw.

"Particularly as the company are threatening to sack any staff who do not accept the contractual changes."

Rowe told the AGM the proposed pay changes could deliver “some of the highest wages in retail” and insisted the pension scheme would still be “generous” despite the cuts.

“We will have further complex decisions to make as we go forward but they will always be taken to give M&S a long term approach," he said.